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Kei te whakaarohia he tikanga hou e hangai ana ki te whakarewa laser whiriwhiri hei whakahaere i te hanganga moroiti o ngā hua i roto i te tukanga hanga. Ka whakawhirinaki te tikanga ki te whakaputanga o ngā ngaru ultrasonic kaha-teitei i roto i te puna rewa mā te hihi laser matatini kua whakatikatikaina. E whakaatu ana ngā rangahau whakamātautau me ngā whakatauira tau he mea whaihua tēnei tikanga whakahaere ā-hangarau, ā, ka taea te whakauru pai ki roto i te hoahoa o ngā mīhini whakarewa laser whiriwhiri hou.
Kua tino tipu te hanga tāpiri (AM) o ngā wāhanga āhua matatini i ngā tekau tau tata nei. Heoi, ahakoa te maha o ngā tukanga hanga tāpiri, tae atu ki te rewa laser whiriwhiri (SLM)1,2,3, te whakatakotoranga whakarewa laser tika4,5,6, te rewa hihi irahiko7,8 me ētahi atu9,10, tera pea he hapa ngā Wāhanga. Ko te nuinga o tēnei nā ngā āhuatanga motuhake o te tukanga whakapakeke puna rewa e pā ana ki ngā pikinga wera teitei, ngā tere whakamatao teitei, me te uaua o ngā huringa whakamahana i roto i ngā rauemi rewa me te whakarewa anō11, e hua ake ai te tipu o te witi epitaxial me te porosity nui12,13. E whakaatu ana ngā hua, me whakahaere ngā pikinga wera, ngā tere whakamatao, me te hanganga koranu, me whakamahi rānei i ngā ru tinana tāpiri mā roto i ngā mara o waho o ngā āhuatanga rerekē (hei tauira, te ultrasound) kia tutuki ai ngā hanganga witi rite tonu.
He maha ngā tuhinga e pā ana ki te pānga o te maimoatanga wiri ki te tukanga whakapakeketanga i roto i ngā tukanga whakarewa tikanga14,15. Heoi, ko te whakamahi i tētahi mara o waho ki ngā rewa papatipu kāore e whakaputa i te hanganga moroiti rauemi e hiahiatia ana. Mena he iti te rōrahi o te wāhanga wai, ka tino rerekē te āhuatanga. I tēnei take, ka pā nui te mara o waho ki te tukanga whakapakeketanga. Kua whakaarohia ngā pānga hikohiko i roto i ngā mara oro kaha16,17,18,19,20,21,22,23,24,25,26,27, te whakaoho pewa28 me te oscillation29, ngā pewa plasma pulsed30,31 me ētahi atu tikanga32. Tāpirihia ki te papa mā te whakamahi i tētahi pūtake ultrasound kaha-teitei o waho (i te 20 kHz). Ko te whakatikatika witi i puta mai i te ultrasound e pā ana ki te rohe whakamatao iti kua piki ake nā te hekenga o te pāmahana me te whakarei ake o te ultrasound ki te whakaputa tioata hou mā te cavitation.
I roto i tēnei mahi, i tirotirohia e mātou te āheinga o te whakarerekē i te hanganga o te witi o ngā maitai kore waikura austenitic mā te whakakorikori i te puna rewa ki ngā ngaru oro i hangaia e te reera rewa tonu. Ko te whakarerekētanga kaha o te pānga o te hihi reera ki runga i te reo mimiti mārama ka hua ake he ngaru ultrasonic, ka whakarerekē i te hanganga moroiti o te rauemi. Ka taea te whakauru ngāwari i tēnei whakarerekētanga kaha o te hihi reera ki roto i ngā pūreretā SLM 3D o nāianei. I mahia ngā whakamātautau i roto i tēnei mahi ki runga i ngā pereti maitai kore waikura i whakaatuhia ō rātou mata ki te hihi reera kua whakarerekētia te kaha. Nō reira, i runga i te hangarau, ka mahia te maimoatanga mata reera. Heoi, ki te mahia taua maimoatanga reera ki runga i te mata o ia paparanga, i te wā e hanga ana i te paparanga-i-te-paparanga, ka tutuki ngā pānga ki te rōrahi katoa, ki ngā wāhanga kua tohua rānei o te rōrahi. Arā, ki te hangaia te wāhanga paparanga-i-te-paparanga, ko te maimoatanga mata reera o ia paparanga he rite ki te "maimoatanga rōrahi reera".
I roto i te whakaora ultrasonic e hangai ana ki te haona ultrasonic, ka tohatohahia te kaha ultrasonic o te ngaru oro tū puta noa i te wāhanga, ko te kaha ultrasonic i puta mai i te laser he tino kukū tata ki te wāhi e mimitihia ana te hihi laser. He uaua te whakamahi i te sonotrode i roto i te mīhini whakakotahi moenga paura SLM nā te mea me noho tonu te mata o runga o te moenga paura e whakaatuhia ana e te hihi laser. Hei tāpiri, kāore he ahotea miihini i runga i te mata o runga o te wāhanga. Nō reira, he tata te ahotea oro ki te kore, ā, he kaha te tere o te matūriki ki runga i te mata o runga katoa o te wāhanga. Kāore e taea e te pēhanga oro i roto i te puna rewa katoa te neke ake i te 0.1% o te pēhanga mōrahi i hangaia e te pane whakarewa, nā te mea ko te roanga ngaru o ngā ngaru ultrasonic me te auau o te 20 kHz i roto i te maitai kore waikura he \(\sim 0.3~\text {m}\), ā, ko te Ko te hohonu he iti iho i te \(\sim 0.3~\text {mm}\). Nō reira, he iti pea te pānga o te ultrasound ki te cavitation.
Me mārama ko te whakamahinga o te hihi taiaho kua whakatikatikaina te kaha i roto i te whakatakotoranga whakarewa taiaho tika he kaupapa rangahau nui tēnei35,36,37,38.
Ko te pānga wera o te pānga o te hihi laser ki te rauemi te pūtake mō te nuinga o ngā tikanga laser 39, 40 mō te tukatuka rauemi, pērā i te tapahi41, te whakarewa, te whakapakeke, te keri42, te horoi mata, te whakakoi mata, te whakakanapa mata43, me ētahi atu. Nā te hanganga o te laser i whakaoho ake ngā whanaketanga hou i roto i ngā tikanga tukatuka rauemi, ā, kua whakarapopototia ngā hua tuatahi i roto i ngā arotake me ngā tuhinga poto maha44,45,46.
Me mārama ko ngā mahi kore-pūmau katoa i runga i te reo, tae atu ki te mahi whakapūmau i runga i te reo mimiti, ka hua ake te whakaoho o ngā ngaru oro i roto i taua mea me te whai huatanga nui ake, iti iho rānei. I te tīmatanga, ko te arotahi matua ko te whakaoho laser o ngā ngaru i roto i ngā wai me ngā momo tikanga whakaoho wera o te oro (te whakawhānui wera, te mimiti, te huringa rōrahi i te wā whakawhiti wāhanga, te whakaheke, me ētahi atu) 47, 48, 49. He maha ngā tuhinga poto 50, 51, 52 e whakarato ana i ngā tātaritanga ariā o tēnei tukanga me ōna tono mahi pea.
I muri mai ka kōrerohia ēnei take i ngā huihuinga maha, ā, he whakamahinga tō te whakaoho laser o te ultrasound i roto i ngā tono ahumahi o te hangarau laser53 me te rongoā54. Nō reira, ka taea te whakaaro kua whakatūria te ariā taketake o te tukanga e pā ai te mārama laser pulsed ki tētahi reo mimiti. Ka whakamahia te tirotiro ultrasonic laser hei kimi hapa i ngā tauira i hangaia e SLM55,56.
Ko te pānga o ngā ngaru wiri i hangaia e te taiaho ki ngā rauemi te pūtake o te whaowhia wiri taiaho57,58,59, e whakamahia ana hoki mō te maimoatanga mata o ngā wāhanga i hangaia he tāpiritanga60. Heoi, ko te whakapakari wiri taiaho te mea tino whai hua ki ngā paowhia taiaho nanohekona me ngā mata kua utaina ā-mīhini (hei tauira, me te paparanga wai)59 nā te mea ka whakanui ake te uta ā-mīhini i te pēhanga tihi.
I whakahaerehia ngā whakamātautau hei tirotiro i ngā pānga pea o ngā momo mara ā-tinana ki te hanganga moroiti o ngā rauemi totoka. Kei te Pikitia 1 te hoahoa mahi o te whakatakotoranga whakamātautau. I whakamahia he reiti totoka Nd:YAG kua pāoroorohia e mahi ana i te aratau rere-kore (roa pāorooro \(\tau _L \sim 150~\upmu \text {s}\ )). Ka tukuna ia pāorooro reiti mā roto i tētahi raupapa tātari kiato korekore me tētahi pūnaha pereti wehewehe hihi. I runga i te huinga o ngā tātari kiato korekore, ka rerekē te kaha pāorooro i runga i te ūnga mai i \(E_L \sim 20~\text {mJ}\) ki \(E_L \sim 100~\text {mJ}\). Ka whāngaihia te hihi reiti e whakaatahia ana mai i te wehewehe hihi ki tētahi photodiode hei kohi raraunga i te wā kotahi, ā, e rua ngā calorimeter (photodiode he roa te wā urupare e neke atu ana i te \(1~\text {ms}\)) e whakamahia ana hei whakatau i te taunga mai ki te ūnga me te whakaata mai i te ūnga, me ngā mita mana e rua (photodiode he poto te urupare ngā wā\(<10~\text {ns}\)) hei whakatau i te mana whatu taupatupatu me te mana whakaata. I whakatikatikaina ngā mita karori me ngā mita mana hei homai uara i roto i ngā waeine tino mā te whakamahi i tētahi taputapu kite wera Gentec-EO XLP12-3S-H2-D0 me tētahi whakaata dielectric i whakanohoia ki te wāhi tauira. Arotahi te hihi ki runga i te ūnga mā te whakamahi i tētahi karāhe (paninga Antireflection i \(1.06 \upmu \text {m}\), roa arotahi \(160~\text {mm}\)) me tētahi hope hihi i te mata ūnga 60– \(100~\upmu\text {m}\).
Kauwhata mahi o te whakatakotoranga whakamātautau: 1—reera; 2—hipa reera; 3—tātari mātotoru koretake; 4—whakaahua-ira tukutahi; 5—wehewehe hihi; 6—whakawhitiwhiti; 7—karorimita o te hihi taunga; 8 – karorimita o te hihi whakaata; 9 – mita mana hihi taunga; 10 – mita mana hihi whakaata; 11 – arotahi arotahi; 12 – whakaata; 13 – tauira; 14 – whakawhiti piezoelectric whānui; 15 – kaitahuri 2D; 16 – pūmana iti tūnga; 17 – wae tukutahi; 18 – pūnaha hopu mamati maha-hongere me ngā tere tauira rerekē; 19 – rorohiko whaiaro.
Ka mahia te maimoatanga ultrasonic penei. Ka mahi te laser i roto i te aratau rere-kore; nō reira ko te roanga o te pā o te laser he \(\tau _L \sim 150~\upmu \text {s}\), e tito ana i ngā roanga maha o te tata ki te \(1.5~\upmu \text {s } \) ia. Ko te āhua wā o te pā o te laser me tōna whānuitanga he kōpaki auau-iti me te whakarerekētanga auau-tiketike, me te auau toharite o te \(0.7~\text {MHz}\), e whakaaturia ana i te Pikitia 2.- Ko te kōpaki auau e whakarato ana i te whakamahana me te rewa me te mimiti o te rauemi, ko te wāhanga auau-tiketike e whakarato ana i ngā wiri ultrasonic nā te pānga photoacoustic. Ko te āhua ngaru o te pā ultrasonic i hangaia e te laser ka whakatauhia e te āhua wā o te kaha o te pā o te laser. Kei te \(7~\text {kHz}\) ki te \ (2~\text {MHz}\), ā, ko te auau pokapū ko \(~ 0.7~\text {MHz}\). I hopukina ngā pāorooro nā te pānga whakaahuaorooro mā te whakamahi i ngā transducers piezoelectric whānui i hangaia mai i ngā kiriata polyvinylidene fluoride. Kei te whakaatuhia te āhua ngaru i hopukina me tōna whānuitanga i te Pikitia 2. Me mōhio ko te āhua o ngā pāorooro taiaho he mea noa ki te taiaho aratau rere-kore.
Te tohatoha ā-wā o te kaha o te pā o te taiaho (a) me te tere o te oro i te mata o muri o te tauira (b), ngā irahiko o te pā o te taiaho (c) me te pā oro-ā-oro (d) i toharitehia i runga i te 300 pā o te taiaho (piko whero) mō te pā kotahi o te taiaho (piko kikorangi).
Ka taea e tātou te wehewehe mārama i ngā wāhanga auau-iti me te auau-tiketike o te maimoatanga oro e pā ana ki te kōpaki auau-iti o te pāoro taiaho me te whakarerekētanga auau-tiketike. Ko ngā roangaru o ngā ngaru oro i hangaia e te kōpaki pāoro taiaho neke atu i te \(40~\text {cm}\); nō reira, e tumanakohia ana te pānga matua o ngā wāhanga auau-tiketike whānui o te tohu oro ki te hanganga moroiti.
He uaua ngā tukanga ā-tinana i roto i te SLM, ā, ka puta ngātahi i runga i ngā tauine ā-wāhi me te ā-wā rerekē. Nō reira, ko ngā tikanga maha-tauine te mea tino pai mō te tātari ariā o te SLM. Me maha-tinana ngā tauira pāngarau i te tīmatanga. Kātahi ka taea te whakaahua pai i te tikanga me te ahupūngao wera o te reo maha-wāhanga "rewa totoka-wai" e taunekeneke ana me te hau hau kore mahi. Ko ngā āhuatanga o ngā kawenga wera rauemi i roto i te SLM e whai ake nei.
Ko ngā tere whakamahana me te whakamatao tae atu ki te \(10^6~\text {K}/\text {s}\) /\text{ nā te hihi laser ā-rohe me ngā mātotoru mana tae atu ki te \(10^{13}~\text {W} cm}^2\).
Ko te roa o te huringa rewa-whakapakaritanga kei waenganui i te 1 me te \(10~\text {ms}\), ka whai wāhi tēnei ki te tere o te whakapakaritanga o te rohe rewa i te wā e whakamatao ana.
Ko te tere o te whakamahana o te mata tauira ka hua ake he ahotea thermoelastic teitei i roto i te paparanga mata. He nui te wāhanga (tae atu ki te 20%) o te paparanga paura ka mimiti kaha63, ka hua ake he kawenga pēhanga tāpiri ki runga i te mata hei whakautu ki te tangohanga laser. Nō reira, ka tino whakapēhia e te taumahatanga i puta te āhua o te wāhanga, inā koa ko ngā tautoko tata me ngā huānga hanganga angiangi. Ko te tere whakamahana teitei i roto i te whakamahana laser pulsed ka hua ake he ngaru taumahatanga ultrasonic e horapa ana mai i te mata ki te papa. Hei whiwhi raraunga tauanga tika mō te ahotea ā-rohe me te tohatoha taumahatanga, ka mahia he whakatauira mesoscopic o te raruraru whakarerekētanga elastic e hono ana ki te whakawhiti wera me te papatipu.
Ko ngā whārite whakahaere o te tauira ko (1) ngā whārite whakawhiti wera kore pumau, ko te kawe wera e whakawhirinaki ana ki te āhua o te wāhanga (paura, rewa, polycrystalline) me te pāmahana, (2) ngā piki me te heke o te whakarerekētanga rapa i muri i te tangohanga tonu me te whārite whakawhānui thermoelastic. Ka whakatauhia te raruraru uara rohe e ngā āhuatanga whakamātautau. Ka tautuhia te rerenga taiaho kua whakarerekētia ki runga i te mata tauira. Kei roto i te whakamatao convective te whakawhiti wera kawe me te rerenga mimiti. Ka tautuhia te rerenga papatipu i runga i te tatau i te pēhanga mamaoa kua kukū o te rauemi mimiti. Ka whakamahia te whanaungatanga ahotea-taumahatanga elastoplastic i te wā e rite ana te ahotea thermoelastic ki te rerekētanga pāmahana. Mō te mana ingoa \(300~\text {W}\), te auau \(10^5~\text {Hz}\), te tauwehenga wā-poto 100 me te \(200~\upmu \text {m}\) o te diameter hihi whai hua.
E whakaatu ana te Pikitia 3 i ngā hua o te whakatauira tau o te rohe rewa mā te whakamahi i tētahi tauira pāngarau makaro. Ko te diameter o te rohe hanumi he \(200~\upmu \text {m}\) (\(100~\upmu \text { m}\) radius) me te \(40~\upmu \text {m}\) hohonu. E whakaatu ana ngā hua whakatauira ka rerekē te pāmahana o te mata i te rohe i te wā \(100~\text {K}\) nā te nui o te tauwehenga wā poto o te whakarerekētanga pahūtanga. Ko ngā reiti whakamahana \(V_h\) me te whakamatao \(V_c\) kei te raupapa \(10^7\) me te \(10^6~\text {K}/\text {s}\), ia. He pai te whakaae o ēnei uara ki tā mātou tātaritanga o mua64. Ko te rerekētanga raupapa o te rahi i waenga i te \(V_h\) me te \(V_c\) ka hua ake he wera nui o te paparanga mata, ka kore e ranea te kawe wera ki te papa ki te tango i te wera. Nō reira, i te \(t=26~\upmu \text {s}\) ka eke te pāmahana o te mata ki te \(4800~\text {K}\). Ka taea e te mimiti kaha o te rauemi te pēhanga nui rawa atu o te mata tauira, ā, ka tihorea.
Ngā hua whakatauira tau o te rohe rewa o te whakamahana i te pā o te taiaho kotahi i runga i te pereti tauira 316L. Ko te wā mai i te tīmatanga o te pā ki te hohonutanga o te puna rewa e tae ana ki te uara mōrahi ko \(180~\upmu\text {s}\). Ko te isotherm\(T = T_L = 1723~\text {K}\) e tohu ana i te rohe i waenga i ngā āhua wai me ngā āhua totoka. Ko ngā isobar (rārangi kōwhai) e rite ana ki te ahotea hua i tatauhia hei mahi a te pāmahana i te wāhanga e whai ake nei. Nō reira, i roto i te rohe i waenga i ngā isoline e rua (isotherms\(T=T_L\) me ngā isobar\(\sigma =\sigma _V(T)\)), ka pāngia te āhua totoka e ngā kawenga miihini kaha, ka arahi pea ki ngā huringa o te hanganga moroiti.
Ka whakamāramahia anō tēnei pānga i te Pikitia 4a, kei reira te taumata pēhanga i roto i te rohe rewa e tuhia ana hei mahi a te wā me te tawhiti mai i te mata. Tuatahi, e pā ana te whanonga pēhanga ki te whakarerekētanga o te kaha o te pā o te taiaho i whakaahuatia i te Pikitia 2 i runga ake nei. I kitea he pēhanga mōrahi \(10~\text {MPa}\) tata ki te \(t=26~\upmu). Tuarua, ko te rerekētanga o te pēhanga ā-rohe i te pūwāhi whakahaere he rite tonu ngā āhuatanga o te wiri ki te auau o \(500~\text {kHz}\). Ko te tikanga o tēnei ka puta ngā ngaru pēhanga ultrasonic i te mata, kātahi ka horapa ki roto i te papa.
Ko ngā āhuatanga kua tatauhia o te rohe whakarerekētanga e tata ana ki te rohe rewa e whakaaturia ana i te Pikitia 4b. Ka puta ngā ngaru whakarerekētanga elastic e horapa ana ki roto i te papa raro mā te tango i te laser me te ahotea thermoelastic. E kitea ana i te pikitia, e rua ngā wāhanga o te whakaputanga ahotea. I te wāhanga tuatahi o \(t < 40~\upmu \text {s}\), ka piki te ahotea Mises ki \(8~\text {MPa}\) me te whakarerekētanga rite ki te pēhanga mata. Ka puta tēnei ahotea nā te tango i te laser, ā, kāore i kitea he ahotea thermoelastic i roto i ngā pūwāhi whakahaere nā te mea he iti rawa te rohe tuatahi i pāngia e te wera. Ina tukuna te wera ki roto i te papa raro, ka puta te ahotea thermoelastic teitei i runga ake i te \(40~\text {MPa}\).
He pānga nui tō ngā taumata ahotea kua whakarerekētia ki te atanga totoka-wai, ā, koinei pea te tikanga whakahaere e whakahaere ana i te ara totoka. Ko te rahi o te rohe whakarerekētanga he 2 ki te 3 ngā wā nui ake i te rohe rewa. E ai ki te Pikitia 3, ka whakaritea te wāhi o te isotherm rewa me te taumata ahotea e ōrite ana ki te ahotea hua. Ko te tikanga o tēnei ko te hihi laser pulsed e whakarato ana i ngā kawenga miihini teitei i roto i ngā wāhi ā-rohe me te diameter whai hua i waenga i te 300 me te \(800~\upmu \text {m}\) i runga i te wā tere.
Nō reira, ko te whakarerekētanga matatini o te whakamahana laser pulsed ka hua ake te pānga ultrasonic. He rerekē te ara kōwhiringa hanganga moroiti mēnā ka whakaritea ki te SLM kāore he uta ultrasonic. Ko ngā rohe kore pumau kua whakarerekētia ka hua ake ngā huringa pēhanga me te totoro ā-wā i roto i te wāhanga totoka. Nō reira, ka taea te hanganga o ngā rohe witi hou me ngā rohe witi iti. Nō reira, ka taea te whakarerekē ā-tauira i ngā āhuatanga hanganga moroiti, e whakaaturia ana i raro nei. Ko ngā whakatau kua whiwhi ka whakarato i te āheinga ki te hoahoa i tētahi tauira SLM e peia ana e te ultrasound-driven modulation pulse. I tēnei take, ka taea te tango i te inductor piezoelectric 26 e whakamahia ana i ētahi atu wāhi.
(a) Te pēhanga hei mahi a te wā, i tatauhia i ngā tawhiti rerekē mai i te mata 0, 20 me te \(40~\upmu \text {m}\) i te taha o te tuaka o te ōritetanga.(b) Te ahotea Von Mises e whakawhirinaki ana ki te wā i tatauhia i roto i tētahi matihiko totoka i ngā tawhiti 70, 120 me te \(170~\upmu \text {m}\) mai i te mata tauira.
I whakahaerehia ngā whakamātautau ki runga i ngā pereti maitai kore waikura AISI 321H me ngā rahinga \(20\times 20\times 5~\text {mm}\). Whai muri i ia pā o te laser, ka neke te pereti \(50~\upmu \text {m}\), ā, ko te hope o te hihi laser i runga i te mata ūnga he tata ki te \(100~\upmu \text {m}\). Tae atu ki te rima ngā whiti hihi e whai ake nei ka mahia i te ara kotahi hei whakaoho i te whakarewatanga o te rauemi tukatuka hei whakapai ake i te witi. I ngā wā katoa, i sonicated te rohe i whakarewahia anō, i runga i te wāhanga oscillatory o te hihi laser. Ko te hua o tēnei he whakahekenga neke atu i te 5-ngā wā i roto i te horahanga witi toharite. E whakaatu ana te Pikitia 5 me pēhea te huri o te hanganga moroiti o te rohe i whakarewahia e te laser me te maha o ngā huringa whakarewatanga anō (ngā whiti) e whai ake nei.
Ngā kauwhata iti (a,d,g,j) me (b,e,h,k) – te hanganga iti o ngā rohe rewa i te reera, ngā kauwhata iti (c,f,i,l) – te horahanga o ngā kakano tae. Ko te atarangi e tohu ana i ngā matūriki e whakamahia ana hei tatau i te histogram. Ka rite ngā tae ki ngā rohe kakano (tirohia te pae tae kei te tihi o te histogram. Ka rite ngā kauwhata iti (ac) ki te maitai kore-waikura kāore i rongoatia, ā, ko ngā kauwhata iti (df), (gi), (jl) e rite ana ki te 1, 3 me te 5 ngā rewa anō.
Nā te mea kāore te kaha o te pā o te taiaho e rerekē i waenga i ngā haerenga e whai ake nei, he rite tonu te hohonutanga o te rohe rewa. Nō reira, ka "kapi" katoatia e te awaawa e whai ake nei te awaawa o mua. Heoi, e whakaatu ana te histogram ka heke te horahanga witi toharite me te waenga i te piki haere o te maha o ngā haerenga. Tērā pea he tohu tēnei kei te mahi te taiaho ki runga i te papa, kaua ki te rewa.
Tērā pea ka puta te whakatikatika o te witi i te whakamatao tere o te puna rewa65. I whakahaerehia tētahi atu huinga whakamātautau i reira i whakaatuhia ai ngā mata o ngā pereti maitai kore waikura (321H me 316L) ki te hihi laser ngaru tonu i te hau (Pikitia 6) me te korehau (Pikitia 7). Ko te mana laser toharite (300 W me 100 W, ia) me te hohonu o te puna rewa e tata ana ki ngā hua whakamātautau o te laser Nd:YAG i te aratau rere-kore. Heoi, i kitea he hanganga poutū noa.
Hanganga moroiti o te rohe rewa-reera o te reera ngaru tonu (mana pumau 300 W, tere matawai 200 mm/s, maitai kore waikura AISI 321H).
(a) Hanganga moroiti me (b) ngā whakaahua whakarara irahiko o te rohe rewa-reera i roto i te korehau me te reera ngaru tonu (mana pumau 100 W, tere matawai 200 mm/s, maitai kore waikura AISI 316L)\ (\sim 2~\text {mbar}\).
Nō reira, e mārama ana te whakaatu he pānga nui te whakarerekētanga matatini o te kaha o te pā o te laser ki te hanganga moroiti e puta mai ana. E whakapono ana mātou he āhua miihini tēnei pānga, ā, ka puta mai i te whakaputanga o ngā wiri ultrasonic e horapa ana mai i te mata i whakamātaohia o te rewa ki roto i te tauira. I whiwhihia ngā hua rite i roto i te 13, 26, 34, 66, 67 mā te whakamahi i ngā transducers piezoelectric o waho me ngā sonotrodes e whakarato ana i te ultrasound kaha-teitei i roto i ngā rauemi maha tae atu ki te Ti-6Al-4V alloy 26 me te kowiri tira 34 te hua o. Ko te tikanga pea e whakaarohia ana penei. Ka taea e te ultrasound kaha te whakaputa i te cavitation acoustic, e whakaaturia ana i roto i te ultrafast in situ synchrotron X-ray imaging. Ko te hinganga o ngā mirumiru cavitation ka puta he ngaru ru i roto i te rauemi rewa, ko tōna pēhanga o mua ka eke ki te \(100~\text {MPa}\)69. Tērā pea he kaha te kaha o aua ngaru ru ki te whakatairanga i te hanganga o ngā karihi totoka-wāhanga nui i roto i ngā wai nui, ka whakararuraru i te hanganga witi poutū o te hanga tāpiri paparanga-i-te-paparanga.
I konei, ka whakaarohia e mātou tētahi atu tikanga e kawenga ana mō te whakarerekētanga hanganga mā te sonication kaha. I muri tonu i te whakapakeketanga, kei te pāmahana teitei te rauemi e tata ana ki te pūwāhi rewa, ā, he tino iti te ahotea hua. Ka taea e ngā ngaru ultrasonic kaha te whakarerekē i te hanganga witi o te rauemi wera, kua whakapakeketia. Heoi, kei te wātea ngā raraunga whakamātautau pono mō te whakawhirinakitanga pāmahana o te ahotea hua i \(T\lesssim 1150~\text {K}\) (tirohia te Pikitia 8). Nō reira, hei whakamātautau i tēnei ariā, i whakahaerehia e mātou ngā whakatauira hihiri ngota (MD) o te hanganga Fe-Cr-Ni e rite ana ki te maitai AISI 316 L hei aromatawai i te whanonga ahotea hua tata ki te pūwāhi rewa. Hei tatau i te ahotea hua, i whakamahia e mātou te tikanga whakangā ahotea kutikuti MD i whakaahuatia i roto i te 70, 71, 72, 73. Mō ngā tātaitanga taunekeneke interatomic, i whakamahia e mātou te Tauira Atomic Whakauru (EAM) mai i te 74. I whakahaerehia ngā whakatauira MD mā te whakamahi i ngā waehere LAMMPS 75,76. Ka whakaputaina ngā taipitopito o ngā whakatauira MD ki wāhi kē. Ko te MD Ko ngā hua tatau o te ahotea hua hei pānga o te pāmahana e whakaaturia ana i te Pikitia 8 me ngā raraunga whakamātautau e wātea ana me ētahi atu aromatawai77,78,79,80,81,82.
Te ahotea hua mō te maitai kore waikura austenitic AISI 316 me te hanganga tauira versus pāmahana mō ngā whakatauira MD. Ngā inenga whakamātautau mai i ngā tohutoro: (a) 77, (b) 78, (c) 79, (d) 80, (e) 81. Tirohia. Ko te (f)82 he tauira empirical o te whakawhirinakitanga o te ahotea hua-pāmahana mō te ine ahotea in-line i te wā o te hanga tāpiri āwhina-reera. Ko ngā hua o ngā whakatauira MD tauine nui i roto i tēnei rangahau kua tohua ko \(\vartriangleleft\) mō te tioata kotahi mutunga kore kore-hapa me te \(\vartriangleright\) mō ngā witi mutunga kore me te whakaaro ki te rahi toharite o te witi mā te whanaungatanga Hall-Petch Dimensions\(d = 50~\upmu \text {m}\).
Ka kitea i te \(T>1500~\text {K}\) ka heke te ahotea hua ki raro i te \(40~\text {MPa}\). I tētahi atu taha, e matapaetia ana e ngā whakatau tata ko te kaha o te ultrasonic i hangaia e te laser e nui ake i te \(40~\text {MPa}\) (tirohia te Pikitia 4b), he rawaka tēnei hei whakaoho i te rere o te kirihou i roto i te rauemi wera kua whakapakeketia.
I tirotirohia mā te whakamātautau te hanganga moroiti o te maitai kore waikura austenitic 12Cr18Ni10Ti (AISI 321H) i te wā o te SLM mā te whakamahi i tētahi pūtake taiaho pāorooro matatini kua whakarerekētia te kaha.
I kitea te whakaiti i te rahi o te witi i roto i te rohe rewa taiaho nā te rewa anō o te taiaho i muri i te 1, 3, 5 rānei ngā haerenga.
E whakaatu ana te whakatauira makarohiko ko te rahi i whakatauhia o te rohe ka pā pai pea te whakarerekētanga ultrasonic ki te taha whakatōtika kei te \(1~\text {mm}\).
E whakaatu ana te tauira MD moroiti kua tino heke te kaha whakaputa o te maitai kore waikura austenitic AISI 316 ki te \(40~\text {MPa}\) tata ki te ira rewa.
Ko ngā hua i puta mai e kī ana i tētahi tikanga mō te whakahaere i te hanganga moroiti o ngā rauemi mā te whakamahi i te tukatuka taiaho matatini kua whakarerekētia, ā, ka taea te whakamahi hei pūtake mō te waihanga i ngā whakarerekētanga hou o te tikanga SLM pulsed.
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